Fluid supply control



Jan. 11,1944. p, DUGAN 2,339,005

FLUID' SUPPLY CONTROL Filed May 21, 1941 2 Sheets-Sheet l INVENTOR. PETER J 006/! ATTOR/Vffd Jan. 11, 1944. ,J DUGAN 2,339,005

FLUID SUPIPLY CONTROL Filed May 21, 1941 2 Sheets-Sheet 2 INVENTOR. PETER I. 0064 tions in pressure from Patented Jan. 11, 1944 UNITED STATES PATENT OFFICE assaoos FLUID SUPPLY common 7 Peter J. Dugan, Crestwood, N. Y. Application May 21, 1941,'Serial No. 394.49: 8 Claims. (Cl. 172-239) My invention relates to amethod and apparatus for controlling the supply o f'afluid under pressure and more particularly tofcontrolling' the rate at'which a fluid under pressure is delivered to a distribution system at a reduced pressure.

The objects, features and advantages of my invention will appear from the following description and accompanying drawings in which Fig. 1 illustrates apparatus used in carrying out my invention;

Fig. 2 illustrates a type of polarized relay which may be used in carrying outmy invention; and

Fig. 3 is a diagrammatic drawing of the electric J- circuit for carrying out my invention.

When a fluid, for-instance suchas steam, is supplied at high pressure, it is desirable to reduce the pressure to a pressure. most advantageous for the use to which the'steam is to beput.

For example, it is desirablein using steam for heating purposes to reduce. the pressure to atmospheric pressure when it is passed into the heating system.vv Circulation .under such a condition is obtained by havingthe system under a vacuum. I

In my apparatus I'have included means so that the time during which adjustment of the supply of steam is effected may beregulated in accord- I ance with particular conditions in order tobeutilized most advantageously.

For instance,- in supplying steam at reduced pressure to a heating-system, I havefound that,

greater econo'myresultsii the change in the supply is made in a series of small steps with a short waiting period between each step:- Such an arrangement permits varying conditions in thede- 'mand during the adjustment to equalize themselves and prevents overshooting .thehe'atingrequirements. However, wliere the adjustment is made in this manner, there-may be slight variathe desired pressure" during such adjustment.

Under certain conditions aswhere there is a large continuous demand-at constant pressure even slight variations in pressure maybe undesirable and inthat event the system will be set to give substantially continuous regulation thereby maintaining a constant pressure.

Retering to the drawings in detail, there is a high pressuresupplypipe l through which steam at high pressure is supplied to a pressure reducing valve II and then to a distribution pipe i2 which leads toa heating, system. The pres sure reducing valve II is adjustable to control 1 i is iaccomplished by moving a counter-weighted valve operating lever. I! by means of a cable H which is connected to a drum IS. The drum i5 is driven through reducing gears I6 by an electric motor I! which can be caused to operate in either direction to effect the adjustment of the pressure reducing valve ll.

The electric motor I1 is operated in response to changes in pressure in the distribution pipe l2. These changes in pressure are transmitted to a pressure gage 18 which isarranged to open or close either contacts ilor 20 at predetermined pressures.

when the pressure in the distribution pipe falls below a predetermined value, the pressure gage It will cause a contact carrying arm l8 to come into contact with contact I! thereby completing a circuit connecting a pilot relay 2| to line wires relay 2| to the line wires A and Al. This holding circuit maintains the relay 2i in operation independently of the connection between the arm I 8 and the contact I! which may open due to changes in the pressure before the cycle of operation for the rest of the system has been completed.

The opening of contacts 2 interrupts a circuit connecting a second pilot relay 2! to the line wire A'and thus prevents that pilot relay from operating in the event that the variations in pressure are of sufllcient magnitude to cause the contact carrying arm I8 to come into contact with contact 20 before the-operating cycle of the system has been completed.

The closing of contacts 22 completes a circuit from the line wires A and Al to a motor reversing relay 28 causing that relay to operate. When the motor reversing relay 26 operate's, it closes contacts 21, 28, 29, 30 and 3i and opens contacts 32. The opening of contacts 32 interrupts a circuit connecting a second motor reversing relay to the line wire A and thus prevents the operation oi. that relay while these contacts are open. The closing of contacts 21, 28 and 29 completes a circuit from the line wires A and Al to the armature 83 and the field coil 34 of the valve adjusting motor il so that the motor will rotate mechanism which is the subject or my .co-pending application Serial Number 419,737, now

Patent No. 2,298,687, 01' October 13, 1942. This timing mechanism is placed in operation by the closing of the contacts 33 by the motor reversing relay 26 which completes a circuit connecting a motor 36 Of a motor generator set to the line wires A and AI. This starts the motor 33 which drives a generator 31, the output of which-is connected to a coil 33 a solenoid operated polarized relay 39.

The effect or the coil 33 is opposed by another coil 49 of the polarized relay 39. This coil 43 is connected through a rectifier 4i to the line wires A and Al by the closing of contacts 3i by. the motor reversing relay 26. When sufficient energy-has been built up in the coil 33 by the generator 31 to overcome the effect of the opposing coil 49, the polarized relay 39 will operate to close contacts 42.

In addition. to the coil 33 a load in the form of a variable resistance 43 is connected across the output or the generator 31 for purposes to be described later.

The closing of the contacts 42 by the polarized relay 39 completes a circuit connecting a relay 44 with the line wires A and Al thereby causing that relay to operate, opening contacts 43. The opening oi contacts 43 by the relay 44 interrupts the circuit conecting the pilot relay 2! to the line wire A and the circuit connecting the motor reversing relay 23 to the line wire A. When the circuit to the pilot relay 2! is interrupted, that relay opens contacts 23 and 22 and closes contacts 24. And when the circuit to the motor reversing relay 26 is opened, that relay operates to open contacts 21, 23, 29, 33 and 3i and to close contacts 32. When contacts 21, 23 and 29 are opened, the circuit connecting the valve adjusting motor I! to the line wires A and Al is interrupted and that motor ceases operation.

The opening of the contacts 33 and 3| interrupts the circuit from the line wires A and Al to the motor 36 of the motor generator setand to the coil 43 0f the polarized relay 39, respectively. After the motor 36 of the motor generator set is disconnected from the line wires A and Al the operation of the generator 31 is prolonged by the inertia stored in a flywheel 46 which is carried on and rotates with a shaft connecting the motor and the generator 31. Thus the generator will continue to supply'energy to the coil 38 ofthe polarized relay '39 after the motor'3l hasbeen discon-- nected and since the opposing coil 49 of the polarized relay 39 is also disconnected, the effect oithe coil 33 will keep the contacts 42 closed until the generator 31 has practically come to rest.

In order to overcome the effect of residual magnetism produced'by' the coil 33 in connection with the operation of the polarized relay 39 after the generator 31 comes to rest, a resistance 51 is connected from one side of the rectifier 4i to the line wire Ai, the other side .43. The variable resistance 43v acts as a brake on the generator 31 so that it it is high the generator stops quickly and it it is low the generator I operates longer.

2i and 23 to the line wire A are held open. This prevents the pilot relays from operating and thereby prevents the-operation of the valve adjustlng motor l1.

This delay constitutes a waiting period which may be regulated'to produce the most advanta geous results under given conditions. In supplying steam to a, heating system I have found a period or to seconds to be satisfactory although this may vary with variations in the characteristics of the heating system itseli.

When the electrical energy being supplied to the coil 33 or the polarized relay 39 tallsbelow a certain point, the contacts 42 open interrupting the circuit connecting the relay 44 to the line wires A and Al. when this occurs, the contacts 43 are closed reestablishing the circuit from the pilot relays 2i and 23 to the line wire A thusreverseits operation when the supply exceeds the demand.

When the supply exceeds the demand, the pressure in the distribution system will be greater than required and the contact carryingarm l3. will move to connectthe line wire Al to the contact 29. When this occurs, the operation of the system is exactly the same as has been described with the exception that the direction in which the valve adjusting motor i1 rotates is reversed so that the pressure reducing valve ii will be closed instead 01' being opened. For this purpose when the contact carrying arm i3 contacts with contact 29, a circuit is completed connecting the second pilot relay 23 to the line wires A and Al. This causes the second pilot relay 23 to operate closing contacts 41 and 43 and opening contacts 49. The closing of contacts 41 completes a holding circuit for the pilot relay 25 and the closing of contacts 43 completes a circuit from the line wires A and Al to a second motor reversing relay 33 causing the operation of that relay to close contacts 3i, 32, 33, 34 and 33 and to open contacts 33. The opening or contacts 49 by the pilot relay 23 interrupts the circuit to the other pilot relay and prevents its operation while these contacts 49 remain open. The opening of contacts 33 interrupts the circuit from the first motor reversing relay 26 to the line wire A and thus prevents operation of that relay while these contacts remain open.

The closing or contacts 3|, 32 and 33 connect the valve adjusting motor I I to the line wires A and Also that the motor I! will now operate in a direction to cause the pressure reducing valve to be closed. The closing of contacts 34 connects the motor 36 or the motor generator set to the line wires A and Al and the closing 0'! the assaoos 3 contacts I connects the rectifier II to the line wires A and Al; :The subsequent operation of these devices is the same s that whichhasjalready been described in conjunction with their the motor reverslng' relay 2 6,

In Order to Prevent'over-traveljot the valve" lusting motor u, there are limit switches '51 and "arranged to interrupt the circuit from this valve adjusting motor to the line 'wiresA and Al if the motor reaches an extreme open or closed position of the pressure reducing valve l I. These limit switches are associated with and operated by the drum l5 and the reducing gears it which are driven by the valve adjusting motor II.

" While I have shown and described the inven-- tion as embodied in a specific form, it is understood that various. changes in details maybe made without departing from the scope or the Iclaim: Y a 1. In a system for electrically controlling an 'adjustable pressure reducing valve in response w to variations from a fixed pressure in a fluid distribution system, a reversible valve adjusting controlled by the relays connecting said timing motor, a pair of motor controlling relays, each oi said motor controlling relays respectively being arranged to connect said valve adjusting motor in circuit for rotation in opposite directions, an electrical timing device controlled by theoperation of said relays, and means controlled by said timing device for interrupting the circuits to said relays after a predetermined period of time and termined period of time thereby causing the valve adjusting motor to remaininoperative for a predetermined period after each period or operation.

2. In a'system for electrically controlling an variations from a flxed pressure in'a fluid distribution system, a pressure responsive circuit closing device connected with said distribution, system, amotor reversing relay, circuits condevice for operating said motor reversing relay, a reversible valve adjusting motor, circuits controlled by said motor reversing relay for operating the valve adjusting motor, an electrical timing device, circuits controlled by the motor reversing relay to place said timing device in operation when the valve adjusting motor is operated, and f means controlled by the timing device to interrupt the circuits to the valve adjusting motor after a predetermined period of operation and to maintain such condition for another predetermined period. I

3. In a system iorelectrically -controlling'an adjustable pressure reducing valve in response to variations from a flxed pressure ina fluid distribution system, a pressure responsivecirw cult closing device, a pair, of motor control re lays, circuits controlled by the pressure responsive device operating said motor control relays,

.vice in conjunction with the valve adjusting motor and means controlled by the timing ,dea vice" to interrupt the operation of the valve ad,-

Justing motor after a predetermined period of operation in conjunction withthe operation "or- 5 time and to maintain such condition for another predetermined period of time.

4. In a system for electrically controlling a adjustable pressure regulating valve in-response to variations from a fixed pressure in: a fluid distribution system, a pressure responsivev'de vice, a pair of motor control relays, means controlled by said pressure responsive device act:- ing in response to a decrease in pressure to conmeet one of said relays to a source of electrical energy and means controlled by said-pressure responsive device acting in responseto' an increase in pressure to connect the other of said relays to the source oi electrical-energy a re versible valve adjusting motor, circuits conmvenuon \definedby the appended claims 20 neetingsaid motor to the source of electrical energy, thecircuits for operatingthe motor -in one direction being controlled by one of said relays and the circuits for operating the motor in the opposite direction being controlled by the other relay, an electrical timing device, circuits 0 mined period 01' time and to maintain said interruption ior'another'predetermlned period of time.

5*. Asystem for electrically controllingan ad l I to maintain such condition for another prede- 35 just e pm 6 regulating valve in response to variations from a fixed pressure in a fluid dissive circuit closing device connected to said distribution system. a pair of pilot relays, circuits connecting said relays to a source of electrical 0 energy, said circuits being controlled by the pressure responsivecircuit closing device, one of said circuits being completed in response to a decrease from the fixed pressure and the other in response to an increase from said pressure, trolled by said pressure responsive circuit closing motor in an opposite direction being controlled by the other'motor control relay, an electrical timing device, circuits controlled by said motor control relays connecting said timing device to the source or electrical energy, and means controlled by said timing deviee to interrupt after a predetermined period of time the circuits to the motor control'relays and to maintain such conditionior a 'secondpredetermined period of 1 time thereby causing the valve adjusting motor to be inoperative tor a certain time after each one of said circuits being completed in response [period of operation.

to a decrease from thefixedpressure and the other in response to an increase from said pressure, a reversible valve adjusting motor, circuits controlled by the motor control relays said relays connecting said motor for operation in an appropriate direction in accordance with the pressure condition in the distribution system, an electrical timing device, circuits con- 6. A system for electrically controlling an adjustable pressure regulating valve in response tovariations from a fixed pressure in a fluid distribution system comprising a pressure responoperating the valve adjusting motor, each of energy, said circuits being controlled by the pressure responsive circuit closing device, one of said trolled by the relays operating said timing de-' 76 circuits being completed in response to a de- I I I crease from the tlxedpressure and the other in response to an increase from said pressure, a holding circuit associated with each of said relays, said holding circuits being completed by the operation of the relaysand connecting'the relays to a source oi! electrical energy independently of the pressure responsive closing device, a pair'ot motor control relays, circuits connecting said of electrical energy, an electrical timing device, circuits controlled by said motor control relay connecting the timing device to a source of electrical-energy, and means controlled by said timing device to interrupt the circuit .to the motor control relay after a predetermined period of timejand to maintain such condition for-a secmotor control relays to'a source 0! electrical en-" ergy, each -of said circuits being controlled respectively-b'y one of thepilot relays, a-reversible' eration.

valve adjusting motor,circuits con-necting"said-v' motor to. 'a source, of;electric'al energy, circuits for operating. the motor in, one direction being controlled by one of the motor control relays and the circuits for;operating".the motor in the opposite direction being controlled by the other motor control relay; an' electrical. timing device;circuitsfcontrolled byisaidniotor control. 5 relays connecting said timing device to thesource of' electrical energy, and means controlled. by

said timing device to interrupt after a predetermined period of time the circuitsto the motor control relays and the pilot relay holding circuits 7 and to maintain such condition for a second predetermined period of time thereby causing the jond predetermined period of time'thereby causing the valve adjusting motorto be inoperative foracertain fixed time after each period of op- ,8. In a-system for' electricallycontrollingan gadjustable pressure regulating valve in response to-variations from a fixed pressure in a fluid distribution system, a pressure responsive circuit closing device connected tosaid distribution system,'a pilot relay, a circuit controlled by the pressure responsive device connecting said relay to a source otelectrical energy, said circuit being completed by said pressure responsive device in response to ag-iven variation from the fixed-pressure in saidjdistribution system, a holding circuit valve adjusting motor to be inoperative for a certain timeaiter each periodotoperation;

'7. Ina system for electrically controllingan adjustable pressure regulating valve" in response to variations from a fixed pressure in 'a fluid distribution system, a pressure responsive circuit closing device connected to'said'dist'ribution system, a pilot relay, a circuit controlled by the pressure responsive device connectingsaid relay.

to a source of electrical energy,- said circuit being connecting-saidflpilot relay to a, source of elecitri'cal'ener'gy, independently or said pressure re,- -sponsive device-said holding circuit being completed by the operation of the pilot relay, a motor controlrelay, a circuit controlled-by said pilot relay' connecting said 'motor control relay to a source ofelectrical energy, a valvcadjusting motor, circuitsflcontrolled by sai'ci motor control relay connecting the, valve .ad';iusting motor to. a source of electrical energy, an electrical timing completed by said pressure responsive'device in L a response to a given variation from theflxed pr'esj sure in said distribution system, a-motor control relay, a circuit controlled by said pilot relay connecting said motor control relay to a source 01' electrical energy, a valve adjusting motor, circuits controlled by said motor control .relay connecting the valve adjusting motor to a source a motor to be inoperative for a certain fixed time after each period oi operation.

' PETER J. DUGANX" 

